mTOR was activated during the process of pulmonary fibrosis in vivo and vitro.

Abstract

<p>A) mTOR activation in fibroblast foci of lung tissue in IPF patients. a,b, H&E staining with normal control and IPF lung tissues; Immunohistochemical staining performed with α-SMA (c,d) and p-S6 (e,f) antibodies showed an increase in α-SMA and p-S6 in IPF lung tissues (d, f) compared with the control (c, e). Scale bar = 100 μm. B) mTOR activation in the lung tissues of C57BL/6J mice after bleomycin intra-tracheal injection. a,b, H&E staining with lungs of saline and bleomycin-treated mice; Immunohistochemical staining was performed with α-SMA (c,d) and p-S6 (e,f) antibodies in saline- and bleomycin-treated mouse lung tissues. NS, normal saline. Scale bar = 100 μm. C) mTOR signaling pathway was activated in primary lung fibroblasts isolated from normal controls treated with TGF-β1(5 ng/ml) for 48 h. Western blot analysis of α-SMA and p-S6 in control and TGF-β1-treated primary lung fibroblasts (a). Densitometric quantification of the Western blot in (a) is shown in (b) with α-SMA normalized against GAPDH and (c) with p-S6 normalized against S6. **, P<0.01; *, P<0.05. n = 3. D) mTOR signaling pathway was activated in MRC5 cells (a human fetal lung fibroblast cell line) treated with TGF-β1 (5 ng/ml) for 48 h. Western blot analysis of α-SMA and p-S6 in control and TGF-β1-treated MRC5 cells (a). Densitometric quantification of the Western blot in (a) is shown in (b) with α-SMA normalized against β-actin and (c) with p-S6 normalized against S6. **, p<0.01; *, p<0.05. n = 3.</p